In an electrical supply network containing generators, intermediate transient effects which lead to critical fluctuations in the real power can occur between the generators. To damp out this fluctuation in the real power, reactive power compensators are typically used. Reactive power compensators are also used to stabilize the voltage of the supply network. However, a measured variable providing information on the fluctuations in the real power is required to control such a reactive power compensator. Such a measured variable may be, for example, the load angle of a generator. However, this variable can be determined only indirectly from the generator itself. Therefore, other measured variables, for example, frequency signals, have been used to control the reactive power compensator. A circuit arrangement which uses frequency signals to control a reactive power compensator is disclosed in DE 2,851,871. However, even this measured variable is satisfactory only within limits, since the measured variable actually required is the frequency difference between the generator and the supply network, which once again cannot be measured directly.
DE AS 1,230,126 discloses a device which detects the load angle metrologically in the immediate or non-immediate vicinity of the generator using components which are dependent on the terminal voltage and terminal current. In this case, the synchronous reactance X.sub.d is predetermined. This device is concerned with regulating relatively slow static processes on site at the generator.
The present invention seeks to provide a method for determining the load angle of a generator in an electrical supply network from measured variables which are present locally on a line and a device for implementing that method.